Model for the Protective Oxidation of Mg-Ca Alloys Containing Be at Elevated Temperature

Abstract

The liquid oxidation behavior of Mg-Ca base alloys containing Be has been presented in this paper. The ignition temperature test and microbalance measurement indicated that the oxide film formed at elevated temperature was protective, resulting in the improved oxidation resistance and ignition-proof properties. A Ca-rich zone was found at the very near surface of oxide layer. With Be addition the oxide layer became dense and compact, which was impermeable for the rapid diffusion of oxygen and magnesium through the oxide layer. It was concluded that the formation of BeO in the oxide layer suppressed the continuous growth of the oxide layer.

Influence of Al and Y on the ignition and flammability of Mg alloys

“…Likewise, Choi et al [19] found that increasing Ca content, in the range 0.3-5 wt%, increased the ignition temperature of AZ91 and that Be, in the range 0.002-0.005 wt.%, further increased the ignition resistance. Huang et al [20] produced similar results for pure Mg containing Ca and Be.…”